• Korean journal of applied entomology
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• v.61 no.1
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• pp.221-227
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• 2022

In accordance with Article 6 of the 「Insect Industry Promotion and Support Act」, the National Institute of Agricultural Sciences conducted a fact-finding investigation in the insect industry for related workers in 2020. Most commonly, insect industry workers were involved in production (98.5%), the male ratio was high (80.4%), while those in their 50s comprised 36.4% of the workers. As for the uses of industrial insects, 66.5% was for food and medicine, 12.7% for feed, and 20.7% as pets. The most commonly produced industrial insect species by use were the white-spotted flower chafer (69.6%), Protaetia brevitarsis seulensis (Kolbe), for food and medicine; crickets (31.2%) for feed; and the rhinoceros beetle (45.6%), Allomyrina dichotoma (Linnaeus), as pets. Powder was the most common product form at 68.5%, and live insects constituted 40.9%. Insect farms with an annual income accounted for 77.3%, of which 65.4% had annual sales of less than 20 million won. Market acquisition was rated by most insect industry workers (84.0%) as the primary challenge. In conclusion, although the number of people employed in the insect industry is increasing annually, the number of young insect farmers (20s to 40s) is decreasing. The production of industrial insects was limited to a few species, and more than half of insect farms have very low incomes. Furthermore, insect farms have the greatest difficulty in market acquisition, necessitating the development of utilization technology to promote the consumption of industrial insects.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.133-141
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• 2016

The physicochemical properties, antioxidant capacities, and sensory optimization of taro (Colocasia esculenta) under different aging conditions were investigated to develop black taro. Black taro was processed in three steps (steaming: $95{\pm}3^{\circ}C$ for 1 h; aging: 85, 90, $95^{\circ}C$ for 20, 40, and 60 h; drying: $60^{\circ}C$ for 24 h) and ground into a powder for all experiments. Black taro showed an increased crude fiber content and browning index compared to raw taro. Calcium oxalate contents, reducing sugar contents, moisture contents, and lightness values were decreased during the processing of taro. Improvements in total polyphenol content and antioxidant activity (DPPH, ABTS, FRAP) were observed in the black taro samples aged at higher temperature. Response surface methodology was used for sensory optimization, and the optimum aging conditions with the highest acceptance values were found to be $88.73^{\circ}C$ for 39.50 h for taste, and $88.82^{\circ}C$ for 42.60 h for overall acceptance.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.105-119
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• 1976

Sucrose, glucose, starches hydrolyzates and raw starchy materials hydrolyzates were caramelized using various catalysis and the caramel products were analysed, in order to carry out the basic research for the replacement of caramel coloring. The results obtained were summarized as follows. 1. The caramel which was manufactured by sucrose syrup being pH 3.5 adjusted by sulfuric acid showed strong color intensity and hue as well as good stability in the solutions of table salt, tannin and alcohol. 2. The product caramelized from sucrose syrup being pH 9.5 adjusted by sodium carbonate showed very strong color intensity and black color component, and was quite stable in alcohol solution but not in table salt and tannin solutions. 3. The caramel products made from sucrose syrup using ammonium salts of strong acid like $NH_4Cl$ and $(NH_4)_2SO_4$ as catalyst showed strong color intensity and black color component but hazy apparence in solution of table salt, tannin and alcohol. 4. The product caramelized from glucose syrup being pH 9.5 adjusted by sodium carbonate indicated strong color intensity but weak red color component and was transparent in solution of table salt and alcohol but hazy in tannin solution. 5. In glucose caramel using $NH_4Cl$, $(NH_4)_2SO_4$, $(NH_4)_2CO_3$ and $(NH_4)_2SO_3$ as catalyst, $NH_4Cl$ plot was very weak in color intensity and insufficient in red color component but stable in solution of table salt, tannin and alcohol. In the case of $(NH_4)_2CO_3$, $(NH_4)_2SO_4$ and $(NH_4)_2SO_3$ plots, all products were strong in color intensity but little insufficient in red color component. On the stability in solutions, $(NH_4)_2SO_3$ plot was stable in two solutions expect tannin solution, $(NH_4)_2CO_3$ plot was only stable in alcohol solution and $(NH_4)_2SO_3$ plot was only stable in table salt solution. 6. When the acid hydrolyzed starch syrups without neutralization were caramelized using $(NH_4)_2SO_4$ as catalyst, the potato starch hydrolyzate caramel showed higher in color intensity being similar to its of glucose caramel than sweet potato starch hydrolyzate caramel and corn starch hydrolyzate caramel. 7. Dried sweet potato powder, dried acorns powders, the acorns (from Q. serrata THUNB and Q. acutissima CARR.) powders extracted with water for 7 days and with 50% alcohol solution for 24 hrs were hydrolyzed by sulfuric acid in autoclave at $3.5kg/cm^2$ as pressure for 60 mins, and were caramelized using $(NH_4)_2SO_4$ as catalyst. It was supposed that all of those products were poor quality on color and stability in solutions at the viewpoint of food coloring matter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.455-462
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• 2000

The objective of this study was to examine the physicochemical characteristics of coagulation reaction between loess and red tide organisms (RTO) and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea. The physicochemical characteristics of loess were examined for a particle size distribution, surface characteristics by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrothen closterium and Skeietonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various concentrations of loess, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number. A negative zeta potential of loess increased with increasing pH at $10^(-3)M$ NaCl solution and had -71.3 mV at pH 9.36. Loess had a positive zeta potential of +1,8 mV at pH 1.98, which resulted in a characteristic of material having an amphoteric surface charge. In NaCl and $CaCl_2$, solutions, loess had a decreasing negative zeta potential with increasing $Na^+\;and\;Ca^(+2)$ ion concentration and then didn't result in a charge reversal due to not occurring specific adsorption for $Na^+$ ion while resulted in a charge reversal due to occurring specific adsorption for $Ca^(+2)$ ion. In sea water, loess and RTO showed the similar zeta potential values of -112,1 and -9.2 mV, respectively and sea sand powder showed the highest zeta potential value of -25.7 mV in the clays. EDLs (electrical double-layers) of loess and RTO were extremely compressed due to high concentration of salts included in sea water, As a result, there didn't almost exist EDL repulsive force between loess and RTO approaching each other and then LVDW (London-yan der Waals) attractive force was always larger than EDL repulsive force to easily form a floe. Removal rates of RTO exponentially increased with increasing a loess concentration. The removal rates steeply increased until $800 mg/l$ of loess, and reached $100{\%}$ at 6,400 mg/l of loess. Removal rates of RTO exponentially increased with increasing a G-value. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction. Loess showed the highest RTO removal rates in the clays.